MetaLab is a research tool for aggregating across studies in the cognitive development literature. Currently, MetaLab contains722 effect sizes across meta-analyses in 14 domains of cognitive development, based on data from 204 papers collecting 10771 subjects. These studies can be used to obtain better estimates of effect sizes across different domains, methods, and ages. Using our power calculator, researchers can use these estimates to plan appropriate sample sizes for prospective studies. More generally, MetaLab can be used as a theoretical tool for exploring patterns in development across language acquisition domains.
Datasets tab.Statistical Approach tab.Field Specification tab.Contribute page.Please note that data and visualizations are under development at the moment (Winter 2017) and should not be taken as definitive.
This page provides an overview of all datasets in MetaLab at this moment. All datasets have more detailed descriptions available through their home pages.
We welcome researchers interested in contributing to Metalab. Please contact us at metalab-project@googlegroups.com
Contributions can take various forms:
All analyses on the site are conducted with the metafor package (Viechtbauer, 2010).
Effect size computation is handled by a script, compute_es.R.
Several pre-existing MAs deal with special cases, and these are listed in the script.
Except where noted, formulas are from Hedges & Olkin’s textbook.
The visualizations page uses a multi-level random effects meta-analysis ( rma.mv function of metafor). Random-effect models assume that the true effect can vary between different studies, and therefore allow random effects for each data point. The model also specifies random effects on the level of each paper, since studies within a paper can be assumed to be more similar to each other than to studies from different papers. In addition, we allow correlated random effects within each paper to account for cases where the same infants contributed data to multiple rows.
The meta-analytic models are accessible in the script server.R
This page gives the full specification for each field in the metalab dataset, including: required fields (which must be included for every MA), optional fields (which are only used for some MAs), and derived fields (which are computed by the site).